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Effect of polymer concentration on the structure and performance of PEI hollow fiber membrane contactor for CO2 stripping

Naim R, Ismail AF

J Hazard Mater, 2013 Apr 15;250-251:354-61.
PMID: 23474409 DOI: 10.1016/j.jhazmat.2013.01.083

A series of polyetherimide (PEI) hollow fiber membranes with various polymer concentrations (13-16 wt.%) for CO2 stripping process in membrane contactor application was fabricated via wet phase inversion method. The PEI membranes were characterized in terms of liquid entry pressure, contact angle, gas permeation and morphology analysis. CO2 stripping performance was investigated via membrane contactor system in a stainless steel module with aqueous diethanolamine as liquid absorbent. The hollow fiber membranes showed decreasing patterns in gas permeation, contact angle, mean pore size and effective surface porosity with increasing polymer concentration. On the contrary, wetting pressure of PEI membranes has enhanced significantly with polymer concentration. Various polymer concentrations have different effects on the CO2 stripping flux in which membrane with 14 wt.% polymer concentration showed the highest stripping flux of 2.7 × 10(-2)mol/m(2)s. From the performance comparison with other commercial membrane, it is anticipated that the PEI membrane has a good prospect in CO2 stripping via membrane contactor.
Firefighter satisfaction and happiness at work: how big is the effect?

Muthukumaran M, Mohd Nadzrul Safiq AR, Rosnah I, Nor Hisham M, Ashrul Riezal A, Ismail AG

Med J Malaysia, 2023 May;78(3):287-295.
PMID: 37271837

INTRODUCTION: Firefighter satisfaction plays a crucial role in overall workplace happiness. We seek to quantify the effect size of firefighters' satisfaction with happiness at work after adjusting for socio-demographic attributes.
MATERIALS AND METHODS: This study used data from an online cross-sectional survey that was conducted from 24 June to 24 July 2021 in the Fire and Rescue Department of Malaysia. Firefighters were approached using the saturation sampling technique. They received online surveys via email through the Director of State and follow-up reminders through the Assistant Director of State Operations. A total of two filter questionnaires were employed i.e. type and duration of service. Firefighters stating that they were volunteer/auxiliary firefighters or had been in service for 2 years or less were excluded. In this study, data from 6041 out of 8581 firefighters were included for further analysis. The survey utilised the validated staff satisfaction index (SSI) and the happy career (HC) scale for in-service firefighters. SSI was a dual-dimension index consisting of welfare and protection against hazards at work, with 16 subdimensions. The HC is a five multi-dimensional items scale. Then, we used multiple linear regression to obtain the coefficient of determination while adjusting for age groups, gender, marital status, job grade, years of service and region of service.
RESULTS: A total of 6041 eligible data points were analysed in the study. The mean (±SD) age was 38.70 (8.97) years, of which 95.9% were male. The firefighters were in service for a median of 14 years (Q1, Q3: 8, 21). The firefighter reported higher life satisfaction (mean [SD] = 78.30 [9.15]) than happiness at work (mean [SD] = 77.22 [0.20]). The mean happiness scores differed significantly between years of service groups (p<0.001), region of service (p<0.001), marital status (p=0.029) and grade (p<0.001). Firefighters' satisfaction contributed 42.7% of workplace happiness (βadj=1.096 [95% CI: 1.064, 1.128]; p<0.001) after adjusting for frontline, married, the central region of service and male gender as control variables.
CONCLUSION: Firefighter satisfaction had a large effect size on happiness at work (42.7%). However, the interpretation of this effect size should be done with caution because happiness at work is inseparable from other life dimensions such as stability in matrimonial relationships and finances, involvement in leisure and religious activities and being mentally healthy.
Fulltext Impact of prebiotics on equol production from soymilk isoflavones by two Bifidobacterium species

Mustafa SE, Mustafa S, Ismail A, Abas F, Abd Manap MY, Ahmed Hamdi OA, et al.

Heliyon, 2020 Oct;6(10):e05298.
PMID: 33134584 DOI: 10.1016/j.heliyon.2020.e05298

The influence of commercial prebiotics (fructo-oligosaccharides and inulin) and sugars (glucose and sucrose) on enhancing equol production from soymilk isoflavones by Bifidobacterium longum BB536 and Bifidobacterium breve ATCC 15700 was evaluated in vitro. Sterilized soymilk was inoculated with each bacterial species at 37 °C for 48 h. The growth and β-glucosidase enzyme activity for the two Bifidobacterium species in soymilk throughout fermentation were assessed. The highest viable count for B. breve (8.75 log CFU/ml) was reached at 36 h and for B. longum (8.55 log CFU/ml) at 24 h. Both bacterial species displayed β-glucosidase activity. B. breve showed increased enzyme activity (4.126 U) at 36 h, while B. longum exhibited maximum activity (3.935 U) at 24 h of fermentation. Among the prebiotics screened for their effect in isoflavones transformation to equol, inulin delivered the highest effect on equol production. The co-culture of B. longum BB536 and B. breve ATCC15700 in soymilk supplemented with inulin produced the highest level (11.49 mmol/l) of equol at 48 h of fermentation process. Level of daidzin declined whereas that of daidzein increased, and then gradually decreased due to formation of equol when soymilk was fermented using bifidobacterial. This suggests that the nutritional value of soymilk may be increased by increasing bioavailability of the bioactive ingredients. Collectively these data identify probiotics and prebiotic combinations suitable for inclusion in soymilk to enhance equol production.
Optimization of culture conditions of soymilk for equol production by Bifidobacterium breve 15700 and Bifidobacterium longum BB536

Mustafa SE, Mustafa S, Abas F, Manap MYABD, Ismail A, Amid M, et al.

Food Chem, 2019 Apr 25;278:767-772.
PMID: 30583440 DOI: 10.1016/j.foodchem.2018.11.107

This study analyzed the effect of pH (X1), temperature (X2) and inulin amount (X3) on transformation of isoflavones (daidzin and daidzein) to equol in soymilk fermented with Bifidobacterium spp. All responses significantly (p  0.05) difference between the experimental and predicted values, suggested the suitability of established models in explaining the daidzin and daidzein transformation to equol as a function of pH, temperature and inulin.
Fulltext Low-Slow-Small (LSS) Target Detection Based on Micro Doppler Analysis in Forward Scattering Radar Geometry

Musa SA, Raja Abdullah RSA, Sali A, Ismail A, Rashid NEA

Sensors (Basel), 2019 Jul 29;19(15).
PMID: 31362452 DOI: 10.3390/s19153332

The increase in drone misuse by civilian apart from military applications is alarming and need to be addressed. This drone is characterized as a low altitude, slow speed, and small radar cross-section (RCS) (LSS) target and is considered difficult to be detected and classified among other biological targets, such as insects and birds existing in the same surveillance volume. Although several attempts reported the successful drone detection on radio frequency-based (RF), thermal, acoustic, video imaging, and other non-technical methods, however, there are also many limitations. Thus, this paper investigated a micro-Doppler analysis from drone rotating blades for detection in a special Forward Scattering Radar (FSR) geometry. The paper leveraged the identified benefits of FSR mode over conventional radars, such as improved radar cross-section (RCS) value irrespective of radar absorbing material (RAM), direct signal perturbation, and high resolutions. To prove the concept, a received signal model for micro-Doppler analysis, a simulation work, and experimental validation are elaborated and explained in the paper. Two rotating blades aspect angle scenarios were considered, which are (i) when drone makes a turn, the blade cross-sectional area faces the receiver and (ii) when drone maneuvers normally, the cross-sectional blade faces up. The FSR system successfully detected a commercial drone and extracted the micro features of a rotating blade. It further verified the feasibility of using a parabolic dish antenna as a receiver in FSR geometry; this marked an appreciable achievement towards the FSR system performance, which in future could be implemented as either active or passive FSR system.
Fulltext Method Development and Validation for Omega-3 Fatty Acids (DHA and EPA) in Fish Using Gas Chromatography with Flame Ionization Detection (GC-FID)

Muhammad Alinafiah S, Azlan A, Ismail A, Mahmud Ab Rashid NK

Molecules, 2021 Oct 30;26(21).
PMID: 34771001 DOI: 10.3390/molecules26216592

Gas chromatography with flame ionization detection (GC-FID) has often been used to quantify fatty acids in fish. This study validated the common method for determining omega-3 fatty acids (DHA and EPA) in the raw and cooked warm-water fish, selayang, using GC-FID for subsequent evaluation on EPA and DHA retention using the Weibull model. The EPA and DHA were separated using a high-polarity capillary GC HP-88 column (60 m length, 0.25 mm ID, 0.2 μm DF) with a total run time of 45.87 min. The method was validated in linearity, precision, accuracy, specificity and sensitivity based on ICH requirements. In addition, it was found that the method had a high recovery rate (>95%) and good precision (RSD ≤ 2%) with overall RSDs ranging below 0.001% for both omega-3 PUFA. In conclusion, this method identified and quantified fatty acids and omega-3 accurately and precisely and can be used effectively for routine FAME analysis in fish samples.
Fulltext Using simulation model as a tool for analyzing bus service reliability and implementing improvement strategies

Moosavi SMH, Ismail A, Yuen CW

PLoS One, 2020;15(5):e0232799.
PMID: 32379848 DOI: 10.1371/journal.pone.0232799

Bus services naturally tend to be unstable and are not always capable of adhering to schedules without control strategies. Therefore, bus users and bus service providers face travel time variation and irregularity. After a comprehensive review of the literature, a significant gap was recognized in the field of public transportation reliability. According to literature, there is no consistency in reliability definition and indicators. Companies have their own definition of bus service reliability, and they mostly neglect the passengers' perspective of reliability. Therefore, four reliability indicators were selected in this study to fill the gap in the literature and cover both passengers' and operators' perceptions of reliability: waiting time and on-board crowding level from passengers' perspective, and headway regularity index at stops (HRIS) and bus bunching/big gap percentage from operators' perspective. The primary objective of this research is to improve the reliability of high frequency of bus service and simulation tools currently being used by the public transportation companies. Therefore, a simulation model of bus service was developed to study the strategies to alleviate it. Four different types of strategies were selected and implemented according to Route U32 (Kuala Lumpur) specifications. Model out-put showed that control strategies such as headway-based dispatching could significantly improve headway regularity by almost 62% and the waiting time by 51% on average. Both holding strategies at key stops (previous and Prefol holding) have shown an almost similar impact on reliability indicators. Waiting time was reduced by 44% and 43% after the previous and Prefol Headway strategies were adopted, respectively. However, the implementation of the component of headway-based strategies at the terminal and key stops showed the best impact on reliability, in terms of passenger waiting time. Waiting time and excess waiting time were both significantly reduced by 52.86% and 81.44%, respectively. Nevertheless, the strategies did not show any significant positive effect on the level of crowding during morning peak hours.
Asia-Pacific mussel watch: monitoring contamination of persistent organochlorine compounds in coastal waters of Asian countries

Monirith I, Ueno D, Takahashi S, Nakata H, Sudaryanto A, Subramanian A, et al.

Mar Pollut Bull, 2003 Mar;46(3):281-300.
PMID: 12604061

Contamination of persistent organochlorines (OCs) such as PCBs (polychlorinated biphenyls), DDT and its metabolites (DDTs), HCH (hexachlorocyclohexane) isomers (HCHs), chlordane compounds (CHLs), and HCB (hexachlorobenzene) were examined in mussels collected from coastal waters of Asian countries such as Cambodia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, Philippines, Far East Russia, Singapore, and Vietnam in 1994, 1997, 1998, 1999, and 2001 to elucidate the contamination status, distribution and possible pollution sources and to assess the risks on aquatic organisms and human. OCs were detected in all mussels collected from all the sampling sites investigated. Considerable residue levels of p,p(')-DDT and alpha-HCH were found in mussels and the concentrations of DDTs and HCHs found in mussels from Asian developing countries were higher than those in developed nations suggesting present usage of DDTs and HCHs along the coastal waters of Asian developing countries. On the other hand, lower concentrations of PCBs detected in mussels from Asian developing countries than those in developed countries indicate that PCBs contamination in mussels is strongly related to industrial and activities. To our knowledge, this is a first comprehensive report on monitoring OCs pollution in the Asia-Pacific region.
Bite envenomation by Latrodectus geometricus (Araneae: Theridiidae) spiders in Malaysia

Mokhtar AS, Muslimin M, Mat-Saat AY, Ghazali AM, Ismail AK, Abdul-Aziz NM

Trop Biomed, 2021 Dec 01;38(4):568-577.
PMID: 35001923 DOI: 10.47665/tb.38.4.100

We report two confirmed human bite cases by Lactrodectus geometricus , also known as the brown widow spider. These are the first reported bite envenomation incidents by L. geometricus in Malaysia. The incidents occurred in Tawau, Sabah and Paka, Terengganu. Both men were bitten on their ear while putting on motorcycle helmets. The spiders appeared to have nested in the helmets. The dead specimens were collected and sent to the Invertebrate and Vertebrate Neurobiology Laboratory, Department of Parasitology, Universiti Malaya for identification. The species identity was confirmed by DNA barcoding.
Fulltext Observational study of the status of coronary risk biomarkers among Negritos with metabolic syndrome in the east coast of Malaysia

Mokhsin A, Mokhtar SS, Mohd Ismail A, M Nor F, Shaari SA, Nawawi H, et al.

BMJ Open, 2018 12 04;8(12):e021580.
PMID: 30518581 DOI: 10.1136/bmjopen-2018-021580

OBJECTIVES: To determine the prevalence of metabolic syndrome (MS), ascertain the status of coronary risk biomarkers and establish the independent predictors of these biomarkers among the Negritos.
SETTINGS: Health screening programme conducted in three inland settlements in the east coast of Malaysia and Peninsular Malaysia.
SUBJECTS: 150 Negritos who were still living in three inland settlements in the east coast of Malaysia and 1227 Malays in Peninsular Malaysia. These subjects were then categorised into MS and non-MS groups based on the International Diabetes Federation (IDF) consensus worldwide definition of MS and were recruited between 2010 and 2015. The subjects were randomly selected and on a voluntary basis.
PRIMARY AND SECONDARY OUTCOME MEASURES: This study was a cross-sectional study. Serum samples were collected for analysis of inflammatory (hsCRP), endothelial activation (sICAM-1) and prothrombogenesis [lp(a)] biomarkers.
RESULTS: MS was significantly higher among the Malays compared with Negritos (27.7%vs12.0%). Among the Malays, MS subjects had higher hsCRP (p=0.01) and sICAM-1 (p<0.05) than their non-MS counterpart. There were no significant differences in all the biomarkers between MS and the non-MS Negritos. However, when compared between ethnicity, all biomarkers were higher in Negritos compared with Malays (p<0.001). Binary logistic regression analysis affirmed that Negritos were an independent predictor for Lp(a) concentration (p<0.001).
CONCLUSIONS: This study suggests that there may possibly be a genetic influence other than lifestyle, which could explain the lack of difference in biomarkers concentration between MS and non-MS Negritos and for Negritos predicting Lp(a).
Fulltext Pyrosequencing-based quantitative evaluation of P16 methylation in diffuse large b-cell lymphoma

Mohd. Ridah L.J., Ismail A., A. Talib N., Muhammad N., Hussain F.A., Zainuddin N.

Journal of Biomedical and Clinical Sciences, 2016;1(1):12-17.
MyJurnal

Introduction: Methylation of promoter region of p16 leading to gene silencing has been implicated ina wide range of malignancies including lymphomas. In diffuse large B cell lymphoma (DLBCL) particularly, a varying percentage of epigenetic inactivation of p16 promoter region was observed ranging from 16 -54%. However, quantitative analysis of p16 promoter methylation in DLBCL has not been extensively studied in Malaysia. Objective: This study aims to quantitatively analyse p16 methylation in DLBCL samples using pyrosequencing technique. Methods: Genomic DNA was extracted from 16 formalin-fixed paraffin-embedded lymphoma tissue blocks from patients diagnosed with DLBCL. Samples were retrieved from Hospital Tengku Ampuan Afzan, Pahang and Hospital Universiti Sains Malaysia, Kelantan. Primers were designed to amplify bisulfite-treated DNA targeting p16 promoter region. Methylation status of 7 CpG sites was determined by pyrosequencing. Results: All the 16 samples studied showed promoter methylation of p16. The range of mean methylation percentage was between 18 to 81%. Conclusion: The present study has successfully measured the level of methylation of p16 in all 7 CpG sites despite the limitation in sample size. Since p16 methylation is a common event in our series of DLBCL cases, it is worth including a larger sample size in future studies to increase the chance of finding a significant correlation with clinical parameters.
Fulltext Randomized Controlled Trials of a Psychosocial Intervention for Improving the Cognitive Function among Older Adults: A Scoping Review

Mohd Safien A, Ibrahim N, Subramaniam P, Shahar S, Din NC, Ismail A, et al.

Gerontol Geriatr Med, 2021 08 11;7:23337214211025167.
PMID: 34395815 DOI: 10.1177/23337214211025167

Aim: The goal is to explore available evidence and provide greater clarity to what is described as psychosocial intervention to improve cognitive function among older population with MCI as well as identifying areas for future research. Methods: An electronic literature search of PubMed, Cochrane, Ebscohost, Medline, Scopus, and gray resource was conducted to find articles published in English language between 2010 and September 2020. This review focused on research undertaken using randomized clinical trials study design. We extracted information regarding the publication date, geographical location, study setting, intervention mechanism, type of cognitive measurement used, and outcome of the studies. References of this literature were also reviewed to ensure comprehensive search. Result: Out of 240 potential records found, a total of 27 articles were identified following the first round of screening and deletion of duplicates. Full-text article reviews and analysis in the second round of screening narrowed the selection down to four articles. Another three relevant articles obtained from references were also included making a total of seven articles in the final analysis. Findings: Psychosocial intervention strategies for improvement of cognitive function, done in various setting all over the globe, covered a range of approaches including art therapy, visual art therapy, therapeutic writing therapy, reminiscence activity, and cognitive behavioral approach. Most were conducted in weekly basis within 1-to-2-hour duration of session. Cognitive function of older adult in psychosocial intervention group was significantly improved in two studies. Three studies showed no significant improvement at all in the cognitive function, and another one reported success in improving cognitive function over time in the intervention group than in control group. One study did not describe the interaction effect. Different types of cognitive measurement also were used to quantify different domains of cognitive function in the reviewed studies. Conclusion: The idea of using psychosocial intervention for improving cognitive function has begun to increasingly accepted recently. Findings from the limited studies are encouraging, although the outcome of the cognitive function was mixed. Large-scale and longer duration of psychosocial intervention with bigger sample size is warranted for future studies.
Fulltext Chromosomal 16p microdeletion in Rubinstein-Taybi syndrome detected by oligonucleotide-based array comparative genomic hybridization: a case report

Mohd Fadley MA, Ismail A, Thong MK, Yusoff NM, Zakaria Z

J Med Case Rep, 2012;6:30.
PMID: 22269667 DOI: 10.1186/1752-1947-6-30

Chromosomal aberrations of chromosome 16 are uncommon and submicroscopic deletions have rarely been reported. At present, a cytogenetic or molecular abnormality can only be detected in 55% of Rubinstein-Taybi syndrome patients, leaving the diagnosis in 45% of patients to rest on clinical features only. Interestingly, this microdeletion of 16 p13.3 was found in a young child with an unexplained syndromic condition due to an indistinct etiological diagnosis. To the best of our knowledge, no evidence of a microdeletion of 16 p13.3 with contiguous gene deletion, comprising cyclic adenosine monophosphate-response element-binding protein and tumor necrosis factor receptor-associated protein 1 genes, has been described in typical Rubinstein-Taybi syndrome.
Fulltext The quality of life in hearing impaired adolescents after hearing aid application

Mohd Adibi SMA, Chen NR, Azmir NA, Solahan N, Ismail A, Anuar AZ, et al.

Med J Malaysia, 2013 Aug;68(4):315-22.
PMID: 24145259 MyJurnal

Hearing impairment in adolescents is a major public health problem. According to the World Health Organization (WHO) deafness and hearing impairment are common health problems throughout the world. Hearing impairment generally impairs emotional, social, communication and educational function. The aim of this study was to determine the correlation between duration of hearing aid use and improvements in the quality of life. The cross sectional study was conducted at Jalan Peel Primary Special School and Universiti Kebangsaan Malaysia Medical Center (UKMMC) from July 2010 until June 2011. A total of 21 students with hearing impairment involved in this study with mean age of 12.57 (10 to 19 years old). The subjects were divided into 2 groups: first-time hearing aid users and long standing hearing aid users. The hearing assessment was conducted in the first group and hearing aids were fitted. After 1 month hearing aid fitting, the questionnaires were distributed to both groups. Statistical analysis had showed no relation (p>0.05) between duration of hearing aid use and the improvement in the quality of life. However, regardless of the duration of hearing aid usage, there was improvement in the quality of life as shown by the scores of the questionnaires. In conclusion there was no significant relation between duration of hearing aid use and the improvement in the quality of life. Hearing aids were beneficial for hearing loss students regardless of the duration of the hearing aid usage.
Fulltext The Impact on Family among Down syndrome Children with Early Intervention

Mohammed Nawi A, Ismail A, Abdullah S

Iran J Public Health, 2013 Sep;42(9):996-1006.
PMID: 26060660

BACKGROUND:
Child with Down's syndrome is an individual who is suitable and eligible to receive early intervention services. This study aimed to measure the family outcome among parents of Down syndrome children, on the impact of receiving early intervention and identify the factors influencing it.

METHODS:
A cross sectional was conducted from April 2009 until January 2010 with a total of 125 parents of children with Down syndrome. There are five domains of family outcomes that has been studied which are understanding the strengths, abilities and special needs of children, knowing the rights and talk on children behalf, assisting the child to grow and learn, having a support system and be involved in the community. Children with Down syndrome aged four to 15 years was chosen as the respondents when they were accompanying their children in seven rehabilitation centers or during house visits.

RESULTS:
Family outcomes among parents of Down syndrome children who receive early intervention is better, 67.3 percent, compared to parents of Down syndrome children who receive late intervention, 41.4 percent. There are significant relationship between the acceptance level of intervention, parents education level, family income and the family outcomes. Parents of children who receive early intervention were more positive in understanding the strengths, abilities and special needs of their children compared to other family outcomes.

CONCLUSION:
Families whom children received early intervention had indirectly proved the importance and benefit of early intervention, not only for children with special needs, but for their family as well.

KEYWORDS:
Down syndrome children; intervention; special needs
Incorporation of N-doped TiO2 nanorods in regenerated cellulose thin films fabricated from recycled newspaper as a green portable photocatalyst

Mohamed MA, Salleh WN, Jaafar J, Ismail AF, Abd Mutalib M, Jamil SM

Carbohydr Polym, 2015 Nov 20;133:429-37.
PMID: 26344299 DOI: 10.1016/j.carbpol.2015.07.057

In this work, an environmental friendly RC/N-TiO2 nanocomposite thin film was designed as a green portable photocatalyst by utilizing recycled newspaper as sustainable cellulose resource. Investigations on the influence of N-doped TiO2 nanorods incorporation on the structural and morphological properties of RC/N-TiO2 nanocomposite thin film are presented. The resulting nanocomposite thin film was characterized by FESEM, AFM, FTIR, UV-vis-NIR spectroscopy, and XPS analysis. The results suggested that there was a remarkable compatibility between cellulose and N-doped TiO2 nanorods anchored onto the surface of the RC/N-TiO2 nanocomposite thin film. Under UV and visible irradiation, the RC/N-TiO2 nanocomposite thin film showed remarkable photocatalytic activity for the degradation of methylene blue solution with degradation percentage of 96% and 78.8%, respectively. It is crucial to note that the resulting portable photocatalyst produced via an environmental and green technique in its fabrication process has good potential in the field of water and wastewater treatment application.
Physicochemical characterization of cellulose nanocrystal and nanoporous self-assembled CNC membrane derived from Ceiba pentandra

Mohamed MA, W Salleh WN, Jaafar J, Ismail AF, Abd Mutalib M, Mohamad AB, et al.

Carbohydr Polym, 2017 Feb 10;157:1892-1902.
PMID: 27987909 DOI: 10.1016/j.carbpol.2016.11.078

This research involves the rare utilisation of the kapok fibre (Ceiba pentandra) as a raw material for the fabrication of cellulose nanocrystal (CNC) and self-assembled CNC membranes. The isolation of CNC from Ceiba pentandra began with the extraction of cellulose via the chemical alkali extraction by using 5wt% NaOH, followed by the typical acidified bleaching method and, finally, the CNC production through acid hydrolysis with 60wt% H2SO4 at the optimum time of 60min. The prepared CNC was then employed for the preparation of self-assembled membrane through the water suspension casting evaporation technique. The obtained CNC membrane was characterised in terms of its composition, crystallinity, thermal stability, as well as, structural and morphological features with the use of several techniques including FTIR, XRD, AFM, TEM, FESEM, and TGA. The FESEM and AFM analyses had illustrated the achievement of a self-assembled CNC membrane with a smooth surface and a well-distributed nano-porous structure, with the porosity of 52.82±7.79%. In addition, the findings proved that the self-assembled CNC membrane displayed good adsorption capability indicated by the recorded efficiency of 79% and 85% for 10mg/L and 5mg/L of methylene blue in an aqueous solution, respectively.
Study on a new mechanism of sterilization in imposex affected females of tropical marine neogastropod, Thais sp

Mohamat-Yusuff F, Zulkifli SZ, Otake T, Harino H, Ismail A

J Environ Biol, 2014 Sep;35(5):995-1003.
PMID: 25204078

The morphological expressions and histopathological analysis of the gonads of a tropical marine neogastropod species (Thais sp.) from East Malaysia revealed new evidence of mechanical sterility in the imposex affected females. The gradual development of imposex was classified into five stages (Stage 0 to Stage 4) with three types of sterility conditions; Type A caused prohibition of copulation and capsule formation; Type B prohibits the releasing process of eggs; and gonads in Type C are infertile. Further analysis is needed to confirm, if the gonad malformation in imposex affected snails is generated specifically by tributyltin (TBT) or by other possible factors. The levels of imposex incidence (stages and percentages) were greater in a marina and decreased with increasing distance from the marina. Organotin tissue burden across the sexes showed that dibutyltin (DBT) as well as TBT might be the elements inducing imposex in Thais sp. from Miri in East Malaysia.
Fulltext Impact of Diuron contamination on blood cockles (Tegillarca granosa Linnaeus, 1758)

Mohamat-Yusuff F, Zulkarnain Z, Anuar NZA, Joni AAM, Kusin FM, Mohamed KN, et al.

Mar Pollut Bull, 2020 Dec;161(Pt A):111698.
PMID: 33022498 DOI: 10.1016/j.marpolbul.2020.111698

Examination of the impact of Diuron contamination on blood cockles (Tegillarca granosa) was conducted by combining field screening at three sampling events and a toxicity test. Diuron was extracted using the liquid-liquid extraction (LLE) technique and analyzed using HPLC-UV. The median lethal concentration (LC50) of Diuron on T. granosa was tested under a 72-h exposure. Diuron in water samples ranged from not detected (ND) to 3910 ppb, which was the highest concentration detected in samples after the irrigation water was discharged from the paddy plantation. Diuron was not detected in sediment samples. Mortality of T. granosa ranged from 4.74 to 38.33% with the highest percentages recorded after the release of the irrigation water. The LC50 value of Diuron was 1.84 ppm. This study suggests that irrigation water from paddy plantation that drifts to coastal areas containing Diuron harms T. granosa at the study area.
Toxicity effect of Diuron on gill tissue structure and the tissue residue of blood cockles (Tegillarca granosa)

Mohamat-Yusuff F, Ibrahim DSM, Mukhtar A, Joni AAM, Kusin FM, Mohamed KN, et al.

Mar Pollut Bull, 2021 Dec;173(Pt B):113071.
PMID: 34741924 DOI: 10.1016/j.marpolbul.2021.113071

This study aimed to identify the toxicity effect of Diuron on Tegillarca granosa by determining accumulation in the soft tissues and alteration on the gill tissue structure. Wild stocks T. granosa were grouped to identify the initial Diuron concentration and 48-h exposure in different concentrations (0, 1, 2, 3, and 4 mg·L-1). The Diuron in tissue was extracted using an established procedure and identified using High-Performance Liquid Chromatography (HPLC). Gills were analysed for histopathological study; tissue structure was classified and scored using a developed scoring system. Diuron concentration in the soft tissue of exposed T. granosa was in the range 1.27-8.09 mg·kg-1, w/w and not proportionately increase along with the exposure concentration. The mean index values of the gill histopathology ranged from 5.25-7.67 and classified as moderate to severe. Gills characteristics and T. granosa protective behaviour potentially limit Diuron accumulation in the soft tissue.

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